Image Storage on a Device

Images and videos are usually stored in phones and tablets in a specific location.

Android usually uses an app called Gallery
Apple usually uses and app called Photos

Within these apps you can select one or multiple images by tap and hold (Android) or choosing the Select option (Apple)

Android uses a Share symbol

Apple uses an Export symbol

Tapping these symbols should give a list of apps and other locations where copies of the images can be sent.

Cloud Storage of Images

Devices can be set up to make copies of all the images that have been created on the device.
Be aware that unless specifically set up differently, cloud services are synchronised.
This means that there are copies in the cloud but these only remain while the original is held on a device.
If the image is deleted from the device it will be also deleted from the cloud service at the next synchronisation.